In addition to the symptoms, seasonal allergies cause a great deal of time lost from work or school and wreak havoc with the quality of life. Nasal allergy, asthma and eczema easily ruin a night’s sleep, producing added problems like fatigue, irritability and depression, and trouble with memory and concentration. For children in school, proper treatment of allergic rhinitis improves school performance.
After impact on performance, the most common complication of seasonal allergy is infection, which occurs because allergic inflammation increases susceptibility to microbial invasion. This has been clearly worked out for the increased susceptibility to colds that complicates seasonal allergic rhinitis.
Nasal Allergies and the Common Cold
The interaction between allergic rhinitis and rhinovirus, the group of viruses that causes the common cold, creates a vicious cycle. Rhinovirus enters your cells by attaching to a molecule called ICAM-1, which is a mediator of inflammation. Having nasal allergies increases the levels of ICAM-1 in the cells that line your nose, increasing the ability of rhinovirus to infect you. Rhinovirus infection then further increases the levels of ICAM-1, which aggravates nasal allergies. Laboratory research has shown that zinc, an essential mineral often lacking in modern diets, can bind to ICAM-1 and prevent rhinovirus from attaching to it. This effect of zinc probably explains the benefits of zinc treatment in decreasing severity and duration of the common cold, which has been demonstrated in numerous controlled clinical trials.
Allergic rhinitis also predisposes you to developing allergic sinusitis. The combined disorder, called rhinosinusitis, affects 12.5 percent of the U.S. population and can become chronic. In addition to nasal symptoms, CRS causes postnasal drip, sore throat, cough, facial pain, headache and fatigue. Like simple rhinitis, CRS may interfere with sleep and mental concentration and plays a major role in causing or aggravating asthma. Seasonal allergies also predispose to the development of ear infections, bronchial infections and nasal polyps.
Seasonal Allergies and Systemic Disorders
Seasonal allergies may be complicated by inflammatory disorders in organs not usually considered to be targets for environmental allergens, a manifestation of systemic inflammation. Gastrointestinal disorders that increased in people with seasonal allergies include ulcerative colitis, eosinophilic esophagitis (a cause of heartburn) and lymphoid hyperplasia of the large intestine (a cause of abdominal pain).
Allergic disorders, including asthma, eczema, allergic rhinitis and rhinosinusitis, are associated with an increased risk of weight gain and obesity. Use of prescription antihistamines, an index of clinical allergy, is associated with increased body weight, according to a study done at Yale University utilizing data from the U.S. government’s National Health and Nutrition Examination Survey. The nature of the relationship is uncertain, but mast cell activation, a feature of allergic reactions, can promote the growth of fat cells.
Complications of Steroids
Topically applied steroids inhaled or as creams, may produce side effects because of systemic absorption from inflamed tissues or from local toxicity. Topically applied steroids are a common treatment for seasonal allergies.
Inhaled steroids increase fungal growth in the respiratory tract and may contribute to thrush and other forms of yeast infection. Steroids interfere with wound healing and can cause atrophy of tissues so that nasal steroids may cause nose bleeds and steroid creams may cause thinning of the skin. Other potential complications of inhaled steroids include hoarse voice, weight gain, behavioral change, cataracts, increased intraocular pressure, stunted growth in children and osteoporosis. Psychiatric disorders associated with inhaled steroids among children are infrequent but may be severe. These complications depend upon dose and cumulative exposure.